Measured Dispersion and Attenuation Effects on the Bulk Modulus of Fully-saturated Sedimentary Rocks

Abstract

Summary Investigating experimentally the frequency dependence of elastic moduli provides quantitative informations on the dispersive effects occurring in sedimentary reservoir rocks. Using a stress-strain method, bulk modulus has been measured at varying frequencies. Prior to measuring micro-structurally complex sedimentary rocks, the experimental apparatus accuracy has been assessed using standard samples of well-known properties. Measurements of both dispersion and attenuation prove to be accurate and correlate, over the frequency range of f ∼ 10-3-10-1 Hz. The method is tested on well-known, quartz-pure, Fontainebleau sandstones. Saturating fluids of differing viscosities have been used. Pressure and frequency dependence of the rocks bulk modulus have been obtained. The results are discussed in the framework of the fluid-flow theories.